Patent GB-872815-A (GB)
Title: Bleaching compositions
Inventor: MCDONNELL FRANCIS ROBERT MAXWE
IPC: C11D3/395
Filed: 1958-08-13
Abstract: A bleaching composition comprises a diluent and dichlorocyanuric acid or one of its salts in granular form with a particle size such that at least 70% of it is retained on a 251-micron sieve.  The particles of dichlorocyanuric acid or its salts are preferably of such a size that at least 70% of them will pass a 1676-micron sieve, and they may be produced by aggregating the powdered acid or salt into crumbs by mixing with a liquid, e.g. water, used as a binding agent, pressing the crumbs through a sieve and then drying.  A small amount of an inert binding agent can be allowed to remain in the granular product. Commercial dichlorocyanuric acid containing unchlorinated or trichlorinated acid may be used.  Specified salts of dichlorocyanuric acid are those of sodium, potassium, calcium and barium.  The composition may contain 2-99% by weight of diluent. Detergent-bleaching compositions are obtained if the composition contains 10-50% by weight of an organic detergent, which may be either soap or a soapless detergent, e.g. an alkylaryl sulphonate or an alkyl sulphate.  Detergent bleaching compositions may also contain conventional detergent adjuncts such as alkali metal sulphates, alkaline materials, e.g. alkali metal carbonates, silicates and phosphates, e.g. orthophosphates or water-soluble condensed phosphates, such as tripolyphosphates and pyrophosphates, sodium carboxymethyl cellulose and fluorescent brightening agents.  The p compositions may contain an alkaline material, e.g. one of those mentioned as alkaline adjuncts, in sufficient quantity to give a pH of 8-11 to an aqueous solution of the composition to promote bleaching.ALSO:A detergent-bleaching composition comprises an organic detergent, which may be either a soap or a soapless detergent, e.g. an alkylarylsulphonate or an alkyl sulphate, and dichlorocyanuric acid or one of its salts in granular form with a particle size such that at least 70% of it is retained on a 251-micron sieve.  The particles of dichlorocyanuric acid or its salts are preferably of such a size that at least 70% of them will pass a 1676-micron sieve, and they may be produced by aggregating the powdered acid or salt into crumbs by mixing with a liquid, e.g. water, used as a binding agent, pressing the crumbs through a sieve and then drying.  A small amount of an inert binding agent can be allowed to remain in the granular product.  Commercial dichlorocyanuric acid containing unchlorinated or trichlorinated acid may be used.  Specified salts of dichlorocyanuric acid are those of sodium, potassium, calcium and barium.  The composition may contain 10-50% by weight of the organic detergent and may also contain conventional detergent adjuncts, such as alkali metal sulphates, alkaline materials, e.g. alkali metal carbonates, silicates and phosphates, e.g. orthophosphates or water-soluble condensed phosphates, such as tripolyphosphates and pyrophosphates, sodium carboxymethyl cellulose and fluorescent brightening agents.  The composition may contain an alkaline material, e.g. one of those mentioned as alkaline adjuncts, in sufficient quantity to give a pH of 8-11 to an aqueous solution of the composition.